TUESDAY, Oct. 22 (HealthDay News) -- A diagnosis of pancreatic
cancer usually carries with it a poor prognosis, and the news may
be even worse for those who are obese: It could mean dying two to
three months sooner than pancreatic cancer patients of normal
weight, new research shows.

Prior studies have tied obesity to a higher chance of getting
pancreatic cancer, but the new study asked whether the disease
affects the tumor's aggressiveness and the patient's overall
survival.

"[The new research] adds to the growing body of evidence that obesity is linked to cancer," said Dr. Smitha Krishnamurthi, an associate professor of medicine at the Case Western Reserve University School of Medicine.

The study was published Oct. 21 in the
Journal of Clinical Oncology. Krishnamurthi was not involved
in the new study, but did write a related journal commentary.

Because it is so often asymptomatic and is detected late,
pancreatic cancer remains one of the most deadly tumor types.
According to the American Cancer Society, more than 45,000 people
will be diagnosed with the disease this year, and it will claim
over 38,000 lives.

In the new study, a team led by Dr. Brian Wolpin, an assistant
professor of medicine at the Dana-Farber Cancer Institute and
Harvard Medical School, collected data on more than 900 patients
with pancreatic cancer who took part in either the Nurses' Health
Study or the Health Professionals Follow-Up Study. These patients
were diagnosed during a 24-year period, the researchers said.

After diagnosis, the patients lived for an average of only five
months. Normal-weight patients, however, lived two to three months
longer than obese patients, the researchers found.

This association remained strong even after the researchers took
into account factors such as age, sex, race, ethnicity, smoking and
the stage of the cancer at diagnosis. The study did not, however,
prove a cause-and-effect relationship between weight and length of
survival.

In addition, obese patients were more likely to have more
advanced cancer at the time they were diagnosed compared with
normal-weight patients. Overall, the cancer had already showed
signs of spreading in 72 percent of obese patients at the time of
diagnosis, compared with 59 percent of normal-weight patients.

It also seemed to matter how long the patient had been obese --
the association between weight and survival was strongest for the
202 patients who were obese 18 to 20 years before being diagnosed
with pancreatic cancer.

Krishnamurthi said the reasons for the link aren't clear. She
said the study can't tell us whether shorter survival in obese
patients "was due to biologic changes that can occur in obesity,
such as increased inflammation in the body, or whether the obesity
caused other conditions that interfered with the treatment of
pancreatic cancer."

"We need more research into how obesity may increase cancer rates and/or aggressiveness," she said.

In a statement from the journal, lead author Wolpin said the
research "reinforces the importance of maintaining a healthy weight
throughout your life, which may lead to better outcomes after
diagnosis and help prevent pancreatic cancer from developing."

"While our findings will not affect the way we treat patients today, they provide new leads for investigating the molecular pathways that may be responsible for the survival difference between obese and healthy-weight patients," Wolpin said. "Hopefully, in the future, that research will bring new approaches for treatment of pancreatic cancer."

Another expert agreed.

"This finding may provide clues about the biology of pancreatic cancer that could eventually be useful in treating patients," said Eric Jacobs, strategic director of pharmacoepidemiology at the American Cancer Society.

"At this point, however, the great majority of pancreatic cancer patients, regardless of their weight, will die of their disease within a few years," Jacobs said. "The most important thing to know about obesity and pancreatic cancer is that maintaining a healthy weight throughout life can help lower the risk of ever developing this highly fatal cancer."

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.